Walk far enough in Buenos Aires in March and you will pass under a palo borracho in flower, a fat-trunked silk floss tree wearing a crown of pink. Summer is on its way out. The days are still warm and the evenings soft enough to walk long after dark without a jacket. In a city this flat, that makes March one of the best months to cover real distance on foot. Put the miles in before lunch and look for shade after it.
Save the long walk for a Sunday, when the San Telmo feria runs down Calle Defensa from Plaza de Mayo to Plaza Dorrego, all antique stalls and tango on the cobbles. Before you leave Plaza de Mayo, look down. Around the pyramid at its centre, the white headscarves of the Mothers of Plaza de Mayo are painted on the paving where the women marched for the children who disappeared under the dictatorship. On 24 March, the anniversary of the 1976 coup, very large crowds fill the square for the National Day of Remembrance for Truth and Justice; join them quietly that day or walk somewhere else. Any other Sunday, head south along Defensa and reach Plaza Dorrego before the lunchtime crush.
From there, cut east across the Puerto Madero docks, and past the last of the towers the city simply stops. The Reserva Ecológica Costanera Sur is lagoons and willow scrub on the edge of the Río de la Plata, free to enter, with more than 300 bird species on its list. It shuts on Mondays and in heavy rain or strong wind, but on a fine March Sunday it stays open into the early evening, long enough to follow the paths out to the river.
On a hot afternoon, Palermo has the shade. The Bosques de Palermo, officially Parque Tres de Febrero, spread over some 370 hectares of woods and lakes. Follow the lake shore to the Greek-style bridge and cross into the Rosedal, whose poets' garden has Borges and Shakespeare staring out from their busts.